Abstract: In order to solve the problem that the transmission error and dynamic contact deformation of flexible gear were usually ignored in the gear dynamics research, a flexible multi-body dynamics research method of gear was proposed. Firstly, the three-dimensional model of double involute gear was established by SolidWorks, the gear was made flexible by ANSYS modal analysis, and the rigid body and flexible body dynamics models of double involute gear were respectively established by ADAMS.Then, Hertz contact theory and multi-body dynamics theory were used to respectively simulated rigid and flexible gears. Finally, by comparing the simulation results of rigid and flexible gear, the influence of elastic deformation and vibration of flexible gear on the dynamic characteristics of double involute gear was analyzed, and the tooth deformation of double involute gear and ordinary involute gear was compared and analyzed.The results show that, after the double involute gear gets flexible,taking the average value to calculate the vibration angular velocity of the slave wheel, the average error between the simulation value and the theoretical value is 0.36%, the error value of the rigid-body gear is 56%, and the gear transmission error is reduced. The simulation values of dynamic contact forces of rigid and flexible gears are not different from the theoretical values, and the amplitude of dynamic meshing forces of flexible gears is stable, indicating that the flexible gears play a damping effect in the meshing process. The tooth deformation of the flexible gear is periodic in the process of transmission;during meshing in and meshing out, the tooth translation deformation and angular deformation of double involute gears fluctuate stably, both smaller than those of ordinary involute gears.
Key words:  mechanical transmission; geartransmission error; dynamic contact deformation; dynamic characteristics; rigid bodygear; flexible bodygear; amplitude of dynamic meshing force; vibration reduction